DE2252284B2 - Sealing device for pipe suspension devices for deep boreholes - Google Patents

Description

40

ij If the seal is still permeable, you can

the running gear and the running pipe string taken out and a suitable retrieval tool inserted to replace the sealing device with another suitable sealing device and achieve a proper seal. The actuation of the sealing device can be carried out at the same time with the loosening of the running pipe run. The deformable rubber-elastic seals or packs are generally using them! through the elastically deformable sealing ring stretching screws or other connec tion means that allow replacement with the dei connected to the deformable sealing ring associated metallic ring seal.

In a known sealing device of the type specified at the outset (GB-PS 446 657) is formed in front of the elastically deformable sealing ring and the associated metallic ring seal A unit in its non-sealing state on its inner circumference to form an annular gap with eini this opposite to be sealed You holding surface of an inner device component in det pipe hanger. The metallic ring seal connects the elastically deformable sealing ring with an axially movable piston and a hanger housing. When the sealing device is brought into its sealing state by means of the axially movable piston, the metallic ring seal remains out of contact with the surface of the inner device component to be sealed, while the elastic, deformable sealing ring only closes by axially compressing it with radial expansion towards its central area with the sealing surface to be sealed of the annulus comes into sealing engagement. In the sealing state of the sealing device, only a partial area of the elastically deformable sealing ring has a sealing effect.

The invention relates to a sealing device for pipe suspension devices for deep boreholes, in particular Underwater boreholes, for sealing concentric sealing surfaces that form an annular space of pipe hangers, hanger housings or similar device components that have a deformable Sealing ring made of resilient material, which is deformed in the axial and radial directions can be brought into and out of sealing engagement with the concentric sealing surfaces, and one of the elastic has deformable sealing ring associated metallic ring seal, which the inner and outer The end engages around the circumferential surface of the sealing ring.

In order to put sealing devices of this type in their sealing state, the deformable Sealing ring made of resilient material axially compressed while not twisting The pipe hanger can be secured in place before the flushing and cementing operations begin so that it is ensured that the pipe hanger is not lifted from its support. The sealing effect can be checked before the running tool and tubing string come out of the borehole be retrieved so that the action causing the seal can be increased.

In another known sealing device (US Pat. No. 2,187,839) for pipe hangers from Deep boreholes for sealing concentric sealing surfaces forming an annular space, which have a deformable sealing ring made of elastically flexible material and a metallic one assigned to it Has ring seal which engages around the inner and outer circumferential surface of the sealing ring at the end, Although the entire axial length of the elastic sealing ring and the metallic Ring seal formed unit in their sealing state as a sealing section for sealing the concentric sealing surfaces forming an annular space are available, but this has the Sealing device from the outset such a cross-sectional shape that it corresponds to that of the concentric sealing surfaces formed annulus fills tightly. To insert the sealing device, the latter is elastic deformable sealing ring with the formation of the metallic ring seal as each of two curved sections Wear rings formed axially divided, so that the rubber-elastic material of the deformable Sealing ring on the side opposite the longitudinal slot, a hinge for opening and closing the sealing device forms. This complicates the known sealing device and sets its sealing effect due to the longitudinal division of the elastically deformable sealing ring.

The invention is based on the object with simple

just structural means a sealing device for To create pipe suspension devices of deep boreholes in which in their sealing state under overpass in this from a non-sealing state by axially compressing the elastically deformable Sealing ring whose entire free axial length to ensure and maintain a high sealing effect is available

Starting from a sealing device of the type specified at the outset, this is done according to the invention achieved in that the metallic ring seal is deformable formed and with the sealing surfaces of the annular space in metal-to-metal sealing engagement While the sealing device is in its non-sealing state on its The outer and inner circumference each form an annular gap with the sealing surfaces of the annular space, so that they can be inserted into this in a simple manner, when they are axially compressed, the elastic deformable sealing ring with radial expansion over its entire free axial length the two sealing surfaces of the annular space to ensure a high sealing effect in the Sealing engagement. At the same time, the axial compression of the sealing device makes the deformable formed metallic ring seal with the sealing surfaces of the annulus in metal-to-metal sealing engagement transferred so that the annular gap between the metallic ring seal and the concentric Sealing surfaces are closed so that the elastically yielding material of the deformable Sealing ring cannot flow or be pressed into this gap, which would otherwise reduce the sealing effect would decrease in operation.

There are already in connection with piston-cylinder arrangements (AU-PS 141 256) and also with pipe hanging devices (GB-PS 1 142 803, US-PS 2 885 009) sealing devices become known, in which deformable metallic ring seals are assigned to elastic seals, which however the elastic seals usually encompass only one side and only with one sealing surface an annulus in metal-to-metal sealing engagement can be transferred, with in particular an influx of the rubber-elastic that reduces the sealing effect Material of the elastically deformable sealing ring in with the other sealing surface of one to be sealed Annular space formed annular gap is unavoidable.

The sealing ring made of elastic material preferably has one on one of its two end faces Metal ring as a ring seal, whose areas encompassing the sealing ring at the ends engage with the latter stand and radially expandable in opposite directions and in sealing engagement with the concentric Sealing surfaces can be applied. It is advantageous to have an elastic seal on the other end face of the sealing ring Material, another metal ring is provided as a ring seal, the sealing ring of which is at the end encompassing areas are also in engagement with this and through the latter opposite radially in Sealing engagement with the sealing surfaces are expandable. The areas here form in the circumferential direction an uninterrupted ring barrier as a seal between the sealing surfaces and the sealing ring remaining annular gap.

The sealing areas of the respective metal ring preferably consist of the peripheral edge of the sealing ring between accepting, mutually

opposite, each on the other MetaMring facing lips, which by expansion and deformation into sealing engagement with the opposing lips Sealing surfaces get and that

Cause closing or blocking of the annular gaps. The metal rings can be made of plastically deformable material or of an elastic material, e.g. B. consist of steel, in the latter case the lips are elastic can regress.

An effective and simple, detachable connection of the rubber-elastic sealing ring with the other Sharing without using the usual fasteners is a further embodiment of the invention in that in each case on one of the interconnected parts an undercut groove and on the other Part of a corresponding flange fitted into the groove are provided.

Additional features, advantages and possible uses of the invention emerge from further subclaims; In the following description, an embodiment of the subject matter of the invention is illustrated in more detail in conjunction with the drawing. In the drawing shows
F i g. 1 is a side view, partially shown in longitudinal section, of a pipe suspension device with associated devices in connection with a subsea borehole;

F i g. 2 shows a vertical partial section through the pipe suspension device with some parts shown broken off, the seal in the sealing state is located

F i g. 3 is a partial vertical section, on an enlarged scale, showing the seal in normal non-sealing State shows, and

F i g. 4 shows a section corresponding to FIG. 3, but with the seal shown in the sealing state is.

A typical installation in which the invention is embodied is shown schematically in FIG. 1 in connection with an underwater borehole A , which extends downward from the river bed F A suitable base frame B rests on the river bed, which carries an outer pipe C of relatively large diameter extending downward from an outer pipe hanger D of a cylindrical shape. The outer tube hanger D rests on an outer support surface E of the base frame and is connected to it by means of a suitable locking ring G. Inside the outer pipe C there is an intermediate pipe string H which extends into the borehole and which is suspended in an intermediate pipe hanger / of a cylindrical basic shape. The intermediate pipe hanger / rests on a beveled seat K of the outer pipe hanger D and is connected to it by a locking ring M. By a series of burst valves N a is by means of a suitable connecting piece P, for example of the hydraulic connector of US-PS 3321217, connected to the outer tubing hanger D, wherein the blowout valve, in turn, by a suitable hydraulic or other connector R with one of at a Connecting line T fixed sections existing flexible connector 5 is connected. The connecting line T leads to the drilling rig, which can be arranged on a drilling platform, on a ship or the like. An inner pipe string Y is shown in FIG. 1 in the intermediate pipe hanger / with an inner pipe hanger W, which is sealed in the intermediate pipe hanger / locks

is, let in. In connection with the creation of a seal between the inner pipe hanger W for the inner pipe string and the intermediate pipe hanger / the invention is explained in more detail below.

The intermediate tube hanger / has an obliquely downward S tapering approach 15, above which an inner circumferential ring groove 16 is located. The annular groove 16 takes a split, compressible locking ring 17 with an inner surface 18 chamfered at the top. An inner sealing surface is located above the annular groove 19 of cylindrical shape, and above this sealing surface there is an inner bore 20, which terminates in a further inner, cylindrical surface 21. The cylindrical surface 21 can be the same Have the same diameter as the sealing surface 19. Another, inwardly open circumferential groove 22 in the cylindrical surface 21 accepts a split compressible circlip 23 with a chamfered top Inner surface 24 on which a device (not shown) subsequently used, for example a conveyor pipe hanger, is removable. Above the cylindrical surface 21, the intermediate pipe hanger / another enlarged bore 25, and above this enlarged bore the intermediate tube hanger / Another cylindrical inner surface 26, over which an internal thread 27 in the intermediate pipe hanger / is provided through which it is moved into position on a running gear in a known manner.

The inner pipe hanger IV has a housing 28 with a lower thread 29, via which the inner pipe string Y is attached. On the housing 28 there is a downward-facing, beveled seat 30 which rests on the upward-facing seat 15 of the surrounding intermediate pipe hanger /. Above the Siu 30 there is an area 31 with a smaller outer diameter, by means of which an upwardly pointing shoulder 32 is formed, which comes into engagement with the lower end of the locking ring 17 when the housing is moved past the locking ring 17. Here, the locking ring 17 is initially in its groove 16 in an outwardly expanded state and is then partially compressed inwardly via the shoulder 32 so that the housing 28 is locked in place against upward movement.

Above the shoulder 32 there is an outer cylindrical sealing surface 33 of smaller diameter, which lies radially opposite the inner sealing surface 19 of the intermediate pipe hanger /, when the housing 28 rests on a counter seat, so that an annular channel 34 is formed above this sealing surface 33, the housing 28 has an area 35 of smaller outer diameter with a right-handed Thread 36 on which a seal actuation sleeve or nut 37 with internal thread 38 is screwed adjustable The actuating sleeve 37 carries a sealing device 39 and exerts an axial effect on it Pressure off, so that the sealing device 39 is shortened and is pressed together between the opposing sealing surfaces 19, 33, as in FIG is described below

The Beiätignngshülse 37 is connected at its upper end with a protective sleeve 40, which has an area 41 has a smaller diameter, which engages in the actuating sleeve 37. The protective sleeve 40 has a Number of pins 42 distributed over its circumference, which extend into inverted T-shaped slots 43 of the actuating sleeve 37. On its upper part carries the Protective sleeve a sweeter sealing ring 44, which against the cylindrical inner surface 26 of the intermediate pipe hanger / Seals The protective sleeve can be fitted with a rotating tube that covers part of the running gear (cf. mentioned US-PS 3,492,026) is connected by means of a number of slots 47 distributed on its circumference will. The vertical legs 48 of the / slots open up through an upward facing one Shoulder 49 of the protective sleeve.

When the inner pipe hanger W with the inner pipe string Y attached to it is connected to a running gear and is lowered through the connecting line 7 ″ and the devices connected to it into the position shown in FIG See ring ring 17 is compressed over the upwardly facing shoulder 32, there is a bypass channel enclosing the annulus 34 between the inner pipe hanger tV and the intermediate pipe hanger /. As shown, this environment is in communication with an annular space 62 of the wellbore surrounding the inner pipe string Y and comprises a number circumferentially distributed, longitudinal fluid channels 63 which extend through the housing 28 to the annular space 34 between the opposing sealing surfaces 19, 33. Fluid can thus up through the annular space 64 between the sealing device and the enlarged bore 20 of the intermediate pipe hanger / and then inwardly through a number of fluid openings 65 provided in the upper part of the actuating sleeve 37 and leading into the interior thereof as well as to the drilling rig at the surface of the water, as shown and described in detail in the above-mentioned US Pat. No. 3,492,026.

The sealing device 39 has an upper face or retaining ring 71 which is fastened to the lower region of the actuating sleeve 37 provided with a thread by means of a connecting device. The connecting device has a split retaining ring 72 which lies in an outer groove 73 of the actuating sleeve 37 and in an inner groove 74 of the end ring 71. Between the actuating sleeve 37 and the end ring 71, a thrust bearing 75 is arranged so that the actuating sleeve can be rotated without rotating the end ring 71. As shown, the thrust bearing has an inverted conical surface 76 on the actuating sleeve 37 and a lower, ridge-like counter surface 77 at the upper end of the end ring 71, a bearing ring 78 made of Teflon R being arranged between the surfaces 76 and 77 so that the actuating sleeve 37 can be rotated without turning the upper end ring 71.

The lower end of the end ring 71 holds the upper end of a cylindrical, elastically deformable sealing ring 79 made of rubber-elastic material, such as rubber or rubber-like materials, the lower The end of the sealing ring 79 engages in a lower abutment ring 80 and carries it The abutment ring 80 can be attached to an upwardly facing shoulder 81 of the housing 28 below its sealing surface 33 can be brought to bear when the actuating sleeve 37 moves downward from the position shown in FIG. 3 shown Position is screwed into the position according to Fig.4 to seal the seal To move state.

From the F i g. 3 and 4 it can be seen that the end ring 71 with an undercut or dovetail-shaped groove 82 that opens downwards is in the a corresponding end flange 83 of the eum-

Tl t> 2

Mielastic seal 79 engages to hold ring 71 and seal 79 together. The rubber-elastic sealing ring can be cast or pressed into the end ring 71. In any case, however, the sealing ring 79 is held on the actuating sleeve 37 by the end ring 71. The lower abutment ring 80 accordingly has an upwardly pointing, undercut or dovetail-shaped groove 84 which receives a corresponding lower flange 85 of the sealing ring 79. Thus, the upper and lower rings 71 or 80 and the sealing ring 79 are mechanically connected to one another without the usual fastening means, the retaining ring 72 allowing easy assembly of the combined sealing device on the actuating unit sleeve 37.

According to the invention means are provided for a metal-to-metal seal between the sealing device 39 and the pipe hangers. According to the illustrated embodiment are these means are provided on rings 71 and 80. As can be seen in particular from FIGS. 3 and 4, has the upper end ring 71 opposing annular lips 86 and 87 which protrude downward and from the undercut groove 82 delimiting edge flanges 88 and 89 on the outer and inner circumference of the Front ring 71 diverge. The lips 86 and 87 lie on respective upwardly converging side walls of the sealing ring 79 and normally have an inner position in which the opposing cylindrical sealing surfaces 19 and 33 are released when the sealing ring 79 is moved down as described below. Accordingly, at the lower end of the Sealing ring 79 of the abutment ring 80 opposite, upwardly projecting annular lips 90 and 91, the edge flanges 92 and 93 delimiting the undercut groove 84 on the outer and inner circumference of the abutment ring 80 diverge. The lips 90 and 91 lie on downwardly converging side walls of the sealing ring 79 and, like the lips 8fe and 87, normally have an inner position in which the opposing sealing surfaces 19 and 33 are released when the sealing ring 79 is moved down.

The rings 71 and 80 can be made of stretchable and pliable, respectively Material or made of elastic or spring steel, so that they by deformation after on the outside in a seal causing circumferential contact

tion with the sealing surfaces 19 and 33 as shown in FIG. 4 can get if the Sealing ring 79 is radially deformed by axial compression. The compression of the sealing ring 79 and its radial deformation as well as the radial deformation of the lips 86, 87 and 90, 91 are moved by moving the actuating sleeve 37 in the axial direction from the in F i g. 3 position shown into the position according to FIG. 4 brought about. To move the actuating sleeve 37 down, it is rotated by a running gear (not shown) which engages in the / slots 47 of the protective sleeve 40, so that by means of the threads 36 and 38 on the actuating sleeve or on the housing 28, the actuating sleeve in the direction causing a sealing effect is moved, the end ring 71 remains untwisted.

When the sealing ring 79 is moved down to the position in which the abutment ring 80 on the Shoulder 81 rests, a progressive further downward movement of the actuating sleeve causes an axial Compression of the rubber-elastic sealing ring 79 with resulting radial or lateral Expansion in both directions, making lips 86.87 and 90.91 in circumferential contact with the Sealing surfaces 19 and 33 are pressed. Due to the installation of the metallic Lips on the sealing surfaces create barriers that form the spaces or gaps between the rings 71 and 80 and the sealing surfaces 19 and 33 lock so that the rubber-elastic material of the sealing ring 79 cannot be pressed through or into this column. By further compressing the rubber-elastic sealing ring 79 this is deformed in such a way that it is in immediate elastic Sealing engagement with the sealing surfaces 19 and 33 also comes into contact with the metal lips 86, 87 and 90, 91 a solid metal-on-metal and gap-blocking Sealing engagement with the sealing surfaces 19 and 33 are pressed.

The sealing device according to the invention thus consists of a combination of opposites Directions of metal-to-metal lip seals and a resilient, rubber-elastic intermediate seal created by the sealing ring whose deformation engages the lip seals in sealing with the concentric sealing surfaces of the Pipe hanger holds.

For this purpose 2 sheets of drawings

509510/8

711 ■ Λ:

Claims (3)

Patent claims: i. Sealing device for pipe suspension devices for deep boreholes, in particular underwater boreholes, for sealing concentric sealing surfaces forming an annular space of Pipe hangers, hanger housings or similar device components that have a deformable Sealing ring made of resilient material, which is deformed in an axial and radial direction Direction in and out of sealing engagement with the concentric sealing surfaces can be brought, and has a metallic ring seal assigned to the elastically deformable sealing ring, welehe the inner and outer circumferential surface of the sealing ring engages at the end, characterized in that that the metallic ring seal is designed to be deformable and with the sealing surfaces (19,33) of the annular space (34) in metal-to-metal sealing engagement is transferable. 2. Device according to claim 1, characterized in that the sealing ring (79) made of elastic material on one of its two end faces has a metal ring (71) as an annular seal, the sealing ring (79) end-encompassing areas of which are in engagement with and through this oppositely radially expandable and can be placed in sealing engagement with the concentric sealing surfaces (19, 33). 3. Device according to claim 1 or 2, characterized in that on the other end face of the Sealing ring (79) made of elastic material, another metal ring (80) is provided as a ring seal is, whose end encompassing the sealing ring (79) also engages with this stand and radially opposite through the latter are expandable in sealing engagement with the sealing surfaces (19, 33).